The present invention relates to teat cleaning devices for cleaning the teats of animals.
A problem when milking dairy animals is how to ensue that the teats of the animal are clean before milking commences. As manual teat cleaning is labour-intensive, inefficient and time consuming various machines for cleaning teats have been proposed.
The German patent DD 127 384 describes a device with a plurality of elongated brushes mounted vertically on a holder. The brushes can rotate about their vertical central axis and have horizontally projecting bristles which can brush the surface of any teats introduced vertically down between the brushes. As the teat advances downwards the bristles are bent down and away from the tip of the teat. This device thus suffers from the disadvantage that the bristles do not adequately clean the tip of the teat.
An object of the present invention is to overcome the problems of the prior art teat cleaning devices. These problems are overcome by a teat cleaning device having the features mentioned in the characterising portion of claim 1. Further developments and improvements to the invention are mentioned in the dependent claims.
In the present invention a teat cleaning device has substantially vertically mounted rotatable cleaning means such as brushes which are provided with cleaning elements such as bristles, the ends of which form a brushing surface which at least partly is inclined upwards. Thus a brushing surface can be formed by, for example, the distal ends of bristles, or the distal circumferential surfaces of cleaning disks, which are inclined upwards. In this application all orientations refer to orientations taken up when the device is in use for cleaning a teat and a vertical axis or direction is defined as being parallel to the longitudinal axis of a teat being cleaned. A vertical position which is nearer to an udder to which the teat is attached is defined to be higher than a vertical position which is nearer to the tip of the teat.
Normally cylindrical brushes comprise bristles collected into conical tufts mounted with the narrower proxial end in a cylindrical support. The bristles comprised in the tuft and situated above its longitudinal axis i.e. a radial axis with respect to the cylindrical shaft, are inclined upwards a few degrees (usually less than 5 degrees) even if the longitudinal axis is horizontal. These few degrees are not sufficient to produce the advantageous effects of the present invention. In order to more precisely differentiate the present invention from the prior art it is therefore appropriate to define what is meant by inclined upwards. Thus the expression upwardly inclined is intended to mean that the longitudinal axis of the tuft of bristles is upwardly inclined. In the case of disks then it is the cylindrical circumferential surface which is upwardly inclined. In the case of cleaning devices which have bent cleaning means e.g. flat inner discs with upturned outer discs then it is the plane of symmetry between the upper and lower surfaces of the outer discs which is inclined to the vertical.
A teat is introduced into the device vertically from above. As the teat is introduced into the device the upwardly inclined bristles resp. disc surfaces are bent downwards owing to the weight of the teat and the tips of the bristles resp. disc surfaces move outwards away from the axis of rotation of the brush and consequently nearer to the centre of the teat. Thus during loading with a teat i.e. when in contact with the tip of a teat being introduced past them, the tips of the bristles resp. the disk surfaces project out a greater distance from the axis of rotation then when there is no teat present. Thus the tip of the teat itself as it is being introduced pushes the tips of the bristles resp. disc surfaces into a position where they can clean the tip of the teat. As the teat is introduced further the bristles resp. disc surfaces are bent more by the thicker body of the teat and the tips of the bristles resp. disc surfaces ultimately can be pushed into horizontal or downwardly bent orientations.